Exam 2 - GI Tract Flashcards
Foregut
Oral cavity –> stomach (bile duct)
(esophagus, stomach, proximal duodenum, spleen, liver, gallbladder, pancreas)
Artery: Celiac trunk
Midgut
Duodenum (bile duct) –> Right hepatic flexure
(second half duodenum, jejunum, ileum, cecum, appendix, ascending colon, proximal 2/3 transverse colon)
Artery: Superior mesentaric
Hindgut
Transverse colon –> Rectum
(left portion transverse colon, descending and sigmoid colon, rectum)
Artery: Inferior mesentaric
Visceral peritoneum
serous membrane
surrounds digestive organs
Parietal peritoneum
serous membrane
lines body wall
Intraperitoneal Organs
SALTED SPRSS Stomach Appendix Liver Transverse colon Duodenum (1st part) Small intestines (jejunum and ileum) Pancreas (only tail) Rectum (only upper 3rd) Sigmoid colon Spleen
Retroperitoneal
SADPUCKER Suprarenal glands Aorta and IVC Duodenum (all but 1st part) Pancreas (all but tail) Ureter and bladder Colon (ascending and descending) Kidneys Esophagus Rectum (lower 2/3)
Mesentery
Double layer of peritoneum that occurs as a result of the invagination of the peritoneum by an organ and constitutes a continuity of the visceral and parietal peritoneum.
Functions:
-Holds organs in place
-Sites of fat storage
-Provides a route for circulatory vessels (blood vessels and lymphatic vessels) and nerves
Peritoneal organs
Organs that keep their mesentery
Omentum
double-layered extension or fold of peritoneum that passes from the stomach and proximal part of the duodenum to adjacent organs in the abdominal cavity
Greater omentum
“Beer Belly” (too big = lordosis)
4 layered peritoneal fold, hangs down like apron from greater curvature of stomach and proximal part of the duodenum. Folds back up and attaches to anterior surface of transverse colon and its mesentary
Lesser omentum
Double-layered peritoneal fold that connects the lesser curvature of the stomach and the proximal part of the duodenum to the liver.
3 Mesenteries
Mesentery proper - small intestine
Transverse mesentery
Sigmoid mesocolon
Stomach functions&blood supply
Storage, primarily mechanical breakdown of fibrous food content (3 muscle layers)
Celiac trunk
Gastric pits
Entrance to gastric glands.
Contain mucous neck cells –> produce mucous that protects stomach from acidity –> prevents ulcers
Gastric Parietal Cells
Intrinsic factor
HCl
Chief cells
Pepsinogen
Pepsin
Enteroendocrine cells
G cells secrete gastrin (hormone that promotes muscle activity of the stomach)
Duodenum
12 fingers
retroperitoneal
“Mixing bowl” = pancreatic juice + bile from bile duct + chyme (stomach contents)
Plicae circulares
folds of small intestinal wall –> increase surface area for absorption
Teniae coli
ribbon-like
creates pouch for expansion
Floating kidney
No adipose layer
Kidney drops –> kink in ureter
Hepatic Portal System
1st Capillary Bed
Organs and glands of GI system
Spleen
(absorbs nutrients and toxins from stomach and intestine)
Hepatic Portal System
2nd (Sinusoids) Capillary Bed
Liver
detoxifies the blood
Gallbladder
stores bile
Liver
produces bile and processes blood
Small Intestinal Epithelium
Has intestinal villi - small, finger-like projections that protrude from epithelial lining of small intestine’s wall)
4 layers
1. Outer longitudinal muscle layer
2. Inner circular muscle layer - 1 and 2 together = tunica muscularis, segmentation and peristalsis
3. Submucosa (in duodenum, Brunner’s glands) - loose connective tissue with blood vessels; nutrient absorption
4. Mucosa - folds for increased surface area for absorption
Intestinal crypts
“mucosal glands” lie within lamina propria (lacteal = lymph vessel in small intestine)
Lamina propria
thin layer of loose connective tissue or dense irregular connective tissue that lies under epithelium (with it makes up the mucosa)
Large intestine function
transport waste and absorb water (smooth lining for easier transport)
–>difference structurally and functionally between large and small intestine
exocrine cells of pancrease
enzymes
pancreatic juice –> pancreatic duct
digests carbohydrates and proteins
endocrine cells of pancreas
hormones: insulin
Hepatic portal vein
superior mesenteric vein + splenic vein
Blood: GI tract –> liver
